Best Topology for modelling animal legs
I have modeled many dinosaurs myself; I started out using the approach you're saying the course used (and that approach is still valid), but I have come to prefer the approach used in the youtube video; I just think it better compliments the shape of the hipbone, which you can see a 3D recreation of here:.
The former approach will lend itself to making that whole area more smooth (as you can see in the image you attached), whereas the latter approach lends itself to giving more definition to that hipbone shape (see how visible the hipbone is in this still from Jurassic World: Fallen Kingdom)
It makes it very easy to have edge loops actually following (and thus better bringing out) the curvature of the hipbone; organic modeling is all about having the topology flow with the forms you see in the shape.